Minimum field size.

Returning to our field, I caught a thermal to give two other gliders time
to land
and clear the runway. I was tired out from the bumps; so decided to land
straight in from 491 m 2.1 km out, approximate 1:4 average slope ≈ 14°
at
maximum 70 kt with landing flap (limit 80) and full spoilers.

Took 91 seconds.

No sideslip. Drag varies with the square of the true airspeed. For
example,
increasing airspeed from 60 to 70 increases drag by 36%.

Not long ago another club seriously crunched a glider that did not come out
of
a sideslip before contacting the ground. Possibly there was a side load on
the
gear as it got bent.

I've dealt with power lines on three outlandings. From over a high voltage
line
you do end up a long ways in the field.

You want to be clearing the tower or pole with a fat margin. I fly almost
directly
overhead where I can look down on it. In between it's harder to judge and
the
wires are pretty much invisible.